The present invention relates in general to the processing of synthesized gases, and in particular to a new and useful technique for filtering particles and in particular un-reacted carbon soot, from syngas which is rich in CO and hydrogen.
Partial oxidation (POx) is a method for converting hydrocarbon fuels into a hydrogen-rich gas, e.g. for use in a fuel cell. The synthesis gas, or syngas, produced by partial oxidation is a mixture of gases rich in CO and hydrogen. The partial oxidation process, however, does not achieve 100% conversion of the carbon in the fuel to gases. About 1 to 3% of the carbon remains as un-reacted "soot".
Other partial oxidation processes for making syngas, such as black liquor gasification and coal gasification, also produce soot. Soot is undesirable and can be removed using a suitable filter. However, the filter must be cleaned periodically to prevent plugging and high pressure drop across the filter.
In a POx reactor demonstration test, MTI (McDermott Technology, Inc.) successfully used a ceramic cross or thru wall flow filter. A high pressure (100 psig) nitrogen pulse had to be applied to clean the filter. The nitrogen system pulsed every 15 minutes. Using a larger filter and allowing a higher pressure drop would have lengthened the cycle time, however, commercial electric power plants in general, and mobile power plants in particular, are unlikely to have a source of high pressure nitrogen available.
A simple, reliable, self-contained system is needed for syngas filtering that enables periodic, on-line cleaning of the filters with minimal pressure drop and flow disruption.